Method and apparatus for manufacturing shoes



Feb. 25, 1969 R. HOFFMANN 3,428,98

METHOD AND APPARATUS FOR MANUFACTURING SHQES Filed April 27, 1966 Sheet of 2 Fig-f Fig.2 3

Z j IY 0.6590 g A B 7 RICHARD HOFFMANN INVENToR'.

A'TWRNEY Feb. 25, 1969 R. HOFFMANN 3,428,9

METHOD AND APPARATUS FOR MANUFACTURING SHOES Filed April 27, 1966 Sheet 2 Of 2 Fig. 7

Rama KOFFMHNN v INVEN'FQK'. =AJAW Q n-r-mkmzy United States Patent US. Cl. 12-1 Int. Cl. A43d 25/00 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for automatically manufacturing a multilayer shoe part, such as a front part of a shoe comprising an upper leather shaft portion with a toe cap mounted thereon and lining leather pasted thereon.

Front parts of shoes of the above described kind are manufactured as is well known, in such a manner that the toe or thermoplastic front caps are connected to the upper leather shaft portion by laying and smoothing them there on, the lining leather being applied by adhesive and pressure, that is to say, the application of adhesive to the lining leather and pressing the latter on to the shaft. This is effected in such a manner that the cap is first applied and then the lining leather, coated with adhesive, is placed in position and pressed on.

This method, which is effected manually, is not only time-consuming and complicated, but also there is no guarantee that the cap applied by hand will always retain the exact position on the shaft portion until the pressing is effected. A further disadvantage is that since the thermoplastic toe or front caps are subjected to heat treatment whilst being smoothed or pressed on to the upper leather shaft, and some of the heat is conducted to or into the upper leather shaft portion disposed below it, skilled staff are required for this work in order to reduce wastage as far as possible. This wastage occurs mainly because the thermoplastic toe caps are either insufliciently heated and therefore do not properly adhere to the upper leather shaft, or the upper leather shaft is affected by excessive heat action.

It is an object of this invention to surmount the abovementioned disadvantages and to provide a method and apparatus for manufacturing the front portions of shoes of the above-described type automatically.

According to the present invention there is provided a method of manufacturing a multi-layer shoe part, such as a shoe front having a toe cap provided on an upper leather shaft portion, and lining leather pasted thereover, characterised by the feature that an upper leather shaft portion, with its inner surface facing upwardly, is disposed by hand in a concave mould and undisplaceably secured in its position therein by means of a vacuum, said mould then being moved to a position under a heatable press head adapted to inter-lock with the mould, whereupon, a toe cap is separated from the prepared store of stacked toecaps by means of a suction holder and is brought between the concave mould and the press head in such a manner that the toe cap, at least partly in contact therewith, is pressed away from the suction holder and moved on to the upturned inner surface of the upper leather shaft portion and pressed thereon by the heated press head, the latter and the concave mould then being returned to their respective starting positions whereupon an adhesive is applied to the upper leather shaft portion and toe caps which are still in the concave mould, a lining leather then being disposed on the part provided with adhesive, after which the mould is again moved out to Patented Feb. 25, 1969 its position under the press head, the press head lowered to press the shoe components together and, after release of the now completed shoe front from the press head and the return of the mould to its starting position the completed shoe front is expelled.

All the pressing operations are preferably effected with the application of heat. For this purpose the press-head is heated electrically in the manner of a smoothing iron.

Preferably the adhesive is sprayed on to the inside of the shaft upper leather portion by means of a spray gun.

The special advantage of this method is the feature that practically all the operations can be carried out mechanically and that the smoothing of the thermoplastic toe cap on to the inside of the upper leather of the shaft can be controlled so that the heat given off by the presshead acts on the latter only briefly sufficiently for a good and reliable connection of the toe cap with the shaft upper leather. This is obtained by the fact that, before the upper leather shaft portion is touched by the hot press-head, the thermoplastic toe cap, immediately after it is brought between the concave mould and the hot press-head, is preheated for the pasting operation, at least partly in contact with the press-head, during the relative movement to the concave mould and until the pressing on or into the inside of the upper leather shaft portion, so that no further heating is necessary. The pressure can therefore be very brief so that it is possible to provide even comparatively thin upper leather shaft parts with thermoplastic caps without danger of damaging them by excessive heat action.

The apparatus for carrying out the method of the present invention is characterised by a concave mould, open at the top, and displaceable in the direction of its longitudinal axis, a press head vertically displaceable substantially perpendicularly to the said axis and adapted to interlock with the concave part of the mould, and a suction holder which is both axially displaceable and vertically displaceable perpendicularly to the said axis, these parts being displaceable relative to each other in such a manner that both the mould and the suction holder can co-operate with the press head in one of their terminal positions.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of the apparatus;

FIG. 2 is a perspective view of a concave mould;

FIG. 3 is a plan view of the mould shown in FIG. 2;

FIG. 4 is a perspective view in cross section of a press head;

FIG. 5 is a front view of the press head show in FIG. 4;

FIG. 6 is a front view of a suction holder;

FIG. 7 is a perspective view of a coupling;

FIG. 8 is a plan of the coupling shown in FIG. 7; and

FIG. 9 shows individual layer of a toe cap before they are combined.

From FIG. 1 it can be seen that the apparatus comprises a table-like base on which a frame-like construction 2 is arranged, the individual parts of which are welded together. A concave mould 3 which is open at the top, a press head 4 and a suction holder 5 are provided on the frame-like construction. The mould 3, the press head 4 and the suction holder 5 are all arranged parallel to a common longitudinal axis X-X in a plane perpendicular thereto, the mould 3 being displaceable along this axis, the press head 4 displaceable substantially perpendicularly thereto and the suction holder 5 displaceable both along the axis XX and also displaceable substantially perpendicularly thereto.

For purposes of displacement the mould 3 is provided with slides 6 on both sides of its underside, running on rails 8 by means of rollers 7. For raising and lowering the press head 4 and the suction holder 5, each of these two members is connected indirectly and directly to a piston rod 9 and 10 respectively controlled pneumatically or hydraulically by cylinders 11 and 12 respectively associated therewith. In addition, the suction holder 5 is connected to a cylinder 14 by a piston rod 13 for displacement in the axial direction X-X. An adhesive applicator device 15 is provided above the mould 3 in the end position A of said mould.

A centering pin 16 (FIG. 2 and 3) is provided on a projecting end portion 17 of the mould 3 by means of which, as shown in FIG. 3, an upper leather shaft part 18 having a notch 18a provided for the purpose on its front part, can be centered on the inside of the mould. In FIG. 2, in which the inside of the mould is shown without an upper leather shaft part, suction bores 19 which are provided for retaining by vacuum the inserted and suitably centered shaft part 18, are clearly seen. At one end of the mould 3, or on a part thereof, for example on one of the slides 6, a switch pin 20 is secured for operating an automatic electrical arrangement to be described hereinafter, which switch pin 20 co-operates with a switch 22 mounted on a stationary part of the apparatus, for example a support 21 of the rails 8, in one of the two end positions of the mould 3.

The press head 4, which interlocks with the inside of the concave mould 3, has at one end a bore 23, in a stationary annular portion 24 of which a perforation and a space 25 and 25a respectively are provided in line with each other at the bottom and top respectively, see FIGS. 4 and 5.

Associated with the suction holder 5, which must be displaceable both in the direction of the axis XX and also substantially perpendicularly thereto, are a bearing displaceable perpendicularly to the axis XX, by means of a piston rod 10, in the present case, a spherical bushing 26, and a coupling displaceable in the axial direction XX by means of a piston rod 13. The suction holder 5 consists of a shaft 28 in the spherical bushing 26 and displaceable therein in the axial direction XX, and a suction beak 29 mounted on the underside of the shaft. In order to be able to move the suction beak 29 extending through the spherical bushing 26 into the latter, the bushing 26 has on its lower side a continuous longitudinal slot 30 (FIG. 6). Below the suction beak 29 a magazine 31 is provided for work pieces such as thermoplastic toe caps 32 to be applied, for example, to the upper leather shaft portion 18.

Since, as already stated the suction holder 5 has to execute both a horizontal and also a vertical motion, an arrangement is necessary which permits both movements to be achieved simultaneously, if desired. For this purpose, a coupling 27 is provided, by means of which the shaft 28 is connected to the piston rod 13.

The coupling 27, which is shown in greater detail in FIGS. 7 and 8, has a continuous longitudinal slot 33 in the side facing shaft 28. The shaft 28 of the suction holder 5 has on its free end a ball pin 34 by which the shaft 28 is journalled to slide in the longitudinal slot 33.

All the movements of the press head 4 and of the suction holder 5 are effected pneumatically or hydraulically, the schematically indicated valves 35a to 35 being controlled electrically, a feature however which is not shown here.

The mould 3 may also be moved automatically by a suitable arrangement of an additional cylinder, whilst, however, this control should also be capable of being switched over to manual operation, if necessary, in order to use the apparatus as universally as possible for appropriate work.

The mode of operation of the apparatus is as follows:

In the starting position of the individual displaceable parts of the apparatus, in which these have the position shown in FIG. 1, the upper leather shaft part 18 is disposed in the concave interior of the mould 3 and brought into the appropriate position by means of the centering pin 16 and the notch 18a provided on the upper leather shaft part 18 and firmly secured therein by means of suction applied by the suction bores 19. The mould 3 is then displaced from its one end position A in the direction of the arrow A into its other end position under the press head 4 until the switch pin 20 makes contact with the switch 22. By switching of the switch 22 the electrical arrangement of the apparatus is operated, whereby the valves 35a-35f of the individual cylinders 11, 12 and 14 are controlled as follows:

Valve 35a is opened to admit liquid or gaseous medium whereby the piston rod 10 and, together therewith, the suction holder 5, are moved downwardly in the direction of the arrow B. Simultaneously air is sucked in by the suction beak 29 which, as soon as it becomes disposed on a thermoplastic toe cap 32 in the magazine 31, secures one of them. The valve 35a is closed by the resultant interruption of the flow of suction air and the valve 3512 opened and the piston with the suction holder 5 and the suctionheld toe cap 32 are raised. When their starting position is reached, the valve 35c is opened and the coupling 27, the shaft 28, journalled to be displaceable in the spherical bushing 26, with the suction beak 29 and the toe cap 32 held thereby, are displaced by the piston rod 13 in the direction of the arrow C towards the press head 4 until the suction beak 29 of the portion of the shaft 28 carrying said beak are partly moved into the press head 4. The bore 23 and the spaces 25 and 25a are provided for this purpose, the former accommodating part of the shaft 28 and the latter the suction beak 29. In this connection it must be pointed out that the suction beak 29, whose main object is to feed the toe caps 32 to the upper leather shaft part 18 in a suitable position, is at an angle for the most part in the direction of the arrow C, so that, when the suction holder 5 is moved into the mould 3, the toe cap 32 held by the suction beak is held by the latter over the front part of the upper leather shaft 18, namely at the place where it is to be mounted. The annular portion 24 of the bore 23 has a width equal to the height of the beak 29 so that the gap 25 just accommodates the beak 29 with the cap 32 being disposed with its upwardly turned side against the lower surface of the heated press head 4. Then, as soon as the suction holder 5 is moved into the bore of the press head which has been drilled out and is facing it, the valve 35d is actuated, the press head 4 moves downwardly in the direction of the arrow D to- Wards the mould 3 which is open at the top, the thermo plastic toe cap 32 being pressed off the stationary suction holder 5 or beak 29 and pressed by the press head 4 on to the part of the upper leather shaft located in the mould 3 and the toe cap, which has now been considerably heated during its contact with the hot press head 4, is simultaneously cemented to the inner surface of the upper leather shaft portion. In order that the suction holder 5 does not impede the downward motion of the press head 4, the bore 3 is either designed so that a relative movement perpendicularly to the axis of the suction holder within the press head 4 is possible or, as in the present embodiment, the press head member is provided with the space 25a at the top which is of such a width that the press head 4 can be moved relatively to the suction holder 5 without coming into contact therewith. As soon as the toe cap is pressed off the beak 29, air is again sucked in by the suction beak 29, after which the valve 350 closes and the valve 35d opens and then the valve 35d is closed and the valve 35f opened. By this means, the suction holder 5 and the press head 4 are returned to their starting positions. The mould 3, with the upper leather shaft member having the toe cap cemented thereto, is returned to its original position under the adhesive applicator device 15, in the present case a spray gun, and provided with adhesive by the latter. Then a lining leather 36 (FIG. 9) is placed on the upper leather shaft portion 18 so as to completely overlie the upper leather shaft portion 18, the mould 3 then being moved under the press head 4 again. The switch 22 is then actuated a second time by the switch pin and causes, as a result of the electric circuit, only the valve 35d to open, whereby the press head 4 is again moved downwardly to the mould 3 and the lining leather laid on the upper leather shaft portion is pressed thereon, preferably with the application of heat. Whilst still in the pressing position, the valve 35d closes and valve 55 opens, whereby the press head 4 is again raised. After the second return of the mould 3 to its starting point, the now completed shoe front, consisting of the upper leather shaft portion 18, the toe cap 32 applied thereto and lining leather 36 pasted thereover, can be removed.

The electrical part of the apparatus can be operated in such a manner that the control of the valves 3541-35 may be effected in any desired sequence by means of a stage switch (not shown) having several operable switch positions, for Examples I-lV. Thus, for example, it is possible, if it is assumed that the apparatus is working in the above-described manner in a given switch position, for example stage I, of the said stage switch, that is to say for the manufacture of shoe fronts, to apply in stage II only a toe cap 32after each operation of the switch 22 by the switch pin 20to the upper leather shaft 18, whilst in a switch position stage III, with each movement of the mould 3 under the press head 4, for the latter to press on only the lining leather or the like. Finally, it is also possible, in stage IV, to separate the circuit for individual movement operations or for a plurality of movement operations of individual or several parts, from the automatically controlled programme and to transfer them to another device operated mechanically by hand or foot actuation as desired, for example to a hand-operated or foot-operated lever or the like, so that the use of the apparatus is much more versatile.

Due to the arcuate shape of the shoe fronts assumed during their manufacture, they are already suitably preformed for further use.

Other multi-layer parts, which are intended to be flat for example, can be manufactured by interchanging suitably prefabricated moulds and shape-engaging associated press heads.

The tool smoothing on the toe caps, in the present case the press head, can be heated much more highly compared with that used in the conventional method of manufacture, since, due to the above-mentioned pre-heating of the toe cap, the latter need be pressed only very briefly on to the upper leather shaft portion. This means that the adhesion is extremely durable and, in addition, the upper leather shaft cannot be damaged by the action of heat.

Naturally, the apparatus can also be used for the application of non-thermoplastic toe caps, for which purpose it is necessary, however, for the upper leather shaft located in the mould, before moving out under the press head, to be provided with adhesive on the front surface to be laid on the toe cap.

It should also be mentioned that the press head 4 is provided with bores 37 and terminal contacts 38 for electrical heating cartridges. The supply of current for this purpose is effected by way of a connecting cable (not shown) which is connected to a current source.

I claim:

1. Apparatus for assembly of shoe uppers, toe caps and linings comprising:

(a) a horizontally longitudinally displaceable work supporting mould provided with work securing vaccum means;

(b) a vertically reciprocal press head provided with work securing and heating means movable into register with said mould in a first position and displaced therefrom in a second position;

Cit

(c) conveyor means supplying heated toe caps to said mould, said means including suction support for said caps;

(d) means applying adhesive liquid to a workpiece secured in said mould when said press head is in said second position; and

(e) means applying and pressing lining material to said adhesive covered workpiece.

2. Apparatus according to claim 1 in which the adhesive applying means (d) is a spray gun.

3. An apparatus according to claim 1, wherein the mould (a) is movable on a slide and rollers secured to its underside.

4. An apparatus according to claim 1, wherein the mould has a centering pin provided on a projecting end portion for positioning a leather shaft portion, and suction bores for retaining the leather shaft portion in position on the inner wall of the mould.

5. An apparatus according to claim 1, wherein the press head (b) has a bore at one end defined by a stationary annular part, said annular part being provided with two radial openings in vertical alignment with one another.

6. An apparatus according to claim 1, wherein the conveyor (c) is provided on its lower side with a suction beak adapted to remove work pieces from a storage magazine provided below the suction beak.

7. An apparatus according to claim 1, wherein a switch pin is mounted on the mould (a) for engagement with a corresponding switch mounted on a stationary part of the apparatus in alignment with the switch pin.

8. An apparatus according to claim 1, wherein the conveyor (c) attains an axial movement and a movement perpendicular to said axis between two terminal positions by means of a coupling which is rigidly connected at its side remote from the conveyor to a piston rod of an axially directed piston, said coupling having on its side facing the conveyor a channel extending substantially perpendicularly to said axis and adapted to receive a hearing end of an axially extending shaft, the opposing end of which shaft is rigidly connected to the conveyor, such that the coupling may transmit axial movement from its associated piston to the conveyor whilst simultaneously permitting the conveyor to move perpendicularly to said axis by accommodating consequential movement of said hearing end within said channel.

9. An apparatus according to claim 8, wherein the axially extending shaft has a ball pin for engagement with the channel provided in the coupling.

References Cited UNITED STATES PATENTS 1,630,788 5/1927 Daly 12 146 1,684,052 9/1928 Baynard 1261.3 1,979,461 11/1934 Frazier 36 77 1,983,622 12/1934 Lovell 36-77 2,107,725 2/1938 Brown 12-146 2,150,279 3/1939 Jorgenson 126l.3 1,644,938 10/1927 Molyneux 12 52 2,110,249 3/1938 Walker 156 249 FOREIGN PATENTS 750,993 6/1956 Great Britain.

EARL M. BERGERT, Primary Examiner.

W. E. HOAG, Assistant Examiner.

U.S. Cl. X.R. 

